2,721 research outputs found
Observations of solar energetic particles at a synchronous orbit
The Space Environment Monitors (SEM) on board the Japanese geostationary meteorological satellites (GMS-1 and GMS-2) observed energetic protons, alpha particles and electrons continuously for February 1978 to September 1984. The satellites were at 6.6 Earth radii above 140 deg E equator
Performance evaluation of novel square-bordered position-sensitive silicon detectors with four-corner readout
We report on a recently developed novel type of large area (62 mm x 62 mm)
position sensitive silicon detector with four-corner readout. It consists of a
square-shaped ion-implanted resistive anode framed by additional
low-resistivity strips with resistances smaller than the anode surface
resistance by a factor of 2. The detector position linearity, position
resolution, and energy resolution were measured with alpha-particles and heavy
ions. In-beam experimental results reveal a position resolution below 1 mm
(FWHM) and a very good non-linearity of less than 1% (rms). The energy
resolution determined from 228Th alpha source measurements is around 2% (FWHM).Comment: 13 pages, 10 figures, submitted to Nucl. Instr. and Meth.
Derivation of CPT resonance signals from density-matrix equations with all relevant sublevels of Cs atoms and confirmation of experimental results
Coherent-population-trapping resonance is a quantum interference effect that
appears in the two-photon transitions between the ground-state hyperfine levels
of alkali atoms and is often utilized in miniature clock devices. To
quantitatively understand and predict the performance of this phenomenon, it is
necessary to consider the transitions and relaxations between all hyperfine
Zeeman sublevels involved in the different excitation processes of the atom. In
this study, we constructed a computational multi-level atomic model of the
Liouville density-matrix equation for 32 Zeeman sublevels involved in the
line of Cs irradiated by two frequencies with circularly polarized
components and then simulated the amplitude and shape of the transmitted light
through a Cs vapor cell. We show that the numerical solutions of the equation
and analytical investigations adequately explain a variety of the
characteristics observed in the experiment.Comment: 24 pages, 8 figure
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